Dental chair



A. M. ASAY. DENTAL 0mm,

N0.1 0,490. Pa'tentedFeb. 7, 1854.

UNITED sTATEs PATENT OFFICE.

A. M. ASAY, OF PHILADELPHIA, PENNSYLVANIA.

DENTAL CHAIR.

Specification of Letters Patent No. 10,490, dated February 7, 1854.

To all whom it may concern:

Be it known that I, A. MERRITT ASAY, of the city and county ofPhiladelphia and State of Pennsylvania, have invented a new and usefulImprovement in Dental Chairs; and I do hereby declare that the followingis a full, clear, and exact description of the construction andoperation of the same, reference being had to the annexed drawingsforming part of this specification, in "\vhich Figure 1 is a sideelevation of the chair. Fig. 2 is a side elevation of the elevatingapparatus. Fig. 3 isa plan of the same.

Similar letters in the several figures refer to the same part.

My improvement refers to the method of raising or lowering the seat ofdental or other chairs, and consists in connecting the seat with four ormore arms of horizontal shafts, so as to give it a vertical motion bythe revolution of said shafts, effected by cog wheels upon them, one ofwhich, meshing into a segment rack moved by a screw, operates the wholesystem.

In the drawings a is an iron bottom plate. Z) Z) are two segments of cogwheels, the segment Z) secured to the middle of the shaft 0 and thesegment b. to the middle of the shaft 0, the segment I) meshing into thesegment rack (Z movable longitudinally by the screw 6, as seen in Fig.2, the screw being held stationary by the collars f f,

while the upper extremity of the rack forms the nut. F astened to theshafts c 0' are the arms 9, having in their extremities most remote fromthe shafts the rollers h, which run in the ways or guides m, secured tothe seat of the chair, the pins n upon which the rollers it turnextending beyond the'arms, and by means of the flanges 0 keeping therollers against the ways m, so as to draw the seat up or down astheshafts 0 0' revolve.

This operation is shown in Fig. 2. Whenit is required to move the seatvertically, the crank a" is turned, pushing forward or withdrawing therack and causing a corresponding revolution of the shafts 0 0,

which by means of the arms 9 elevates or nesses.

A. MERRITT ASAY.

WVitnesses:

JOHN THOMPSON,

J. S. CLAR

